Stacked-type dual thermoresponsive switch



United States Patent 3,1817% STAUKED-TYPE DUAL THERMGRESPONSIVE SWETCH John W. Huffman, Mansfield, Ohio, assignor to Pace, line, Mansfield, Ohio, a corporation of Ohio Filed Ian. 31, 1963, Ser. No. 255,331 9 Claims. (Cl. 200-438) This invention relates to thermostat switches and more particularly to a dual switch mechanism for controlling or interrupting both power supply conductors or lines, the switch mechanism incorporating thermoresponsive means for automatically controlling the making and interrupting of a circuit for an electric energy consuming instrumentality or appliance.

Thermostat control switches have been extensively used to make or break the circuit by interrupting or breaking of one current supply conductor or line. In the use of appliances such as room or space heaters, it is desirable for purposes of safety to control the circuit to the appliance by providing means for interrupting both supply conductors when the manual control for setting the range of operation of the switch is moved to an oil position. Furthermore such an arrangement is desirable as it facilitates service and maintenance of the appliance without the necessity of disconnecting the power supply.

An object of the present invention resides in a switch 1 mechanism of the stacked-type embodying a dual switch arrangement for interrupting or connecting both current supply conductors to an appliance, the arrangement embodying thermoresponsive means for automatically controlling current supplied to an appliance with which the switch mechanism may be used.

Another object of the invention resides in a dual switch mechanism for controlling both current supply conductors embodying a thermoresponsive means and a manually adjustable arrangement providing for a positive off position.

Another object of the invention resides in the provision of switch means effective on both current supply conductors or lead lines for interrupting both conductors so that the appliance may be completely isolated from current supply without liability of shock or electrical hazard and avoiding possible damage to the appliance.

Further objects and advantages are Within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE 1 is an enlarged longitudinal sectional view illustrating a form of thermostat switch mechanism of the invention;

FIGURE 2 is a top plan View of the switch mechanism illustrated in FIGURE 1;

FIGURE 3 is a sectional view similar to FIGURE 1 illustrating the position of the various components with the switch members in circuit interrupting positions;

FIGURE 4 is an end elevational view of the arrangement illustrated in FIGURE 3, and

FIGURE 5 is a detail sectional view taken substantially on the line 5- 5 of FIGURE 1.

The switch construction of the invention is especially adapted for controlling the current supply conductors or supply lines for appliances such as air conditioners, electrically energizable space heaters, wall heaters or the like or the same may be used with other current consuming instrumentalities where it is desirable or imperative to provide a positive off position of the switch means.

Referring to the drawings in detail the thermostat 3,185,795 Patented May 25, 1965 switch means embodying dual switch means is illustrated in circuit with a current consuming instrumentality or unit 12, schematically illustrated, which may be a resistance heater or other current consuming device, the switch mechanisms being arranged to interrupt both current supply lines of conductors L1 and L2. The switch mechanism illustrated in the drawings is about twice actual size for use in most installations, but it is to be understood that the size of the switch mechanism and its several components may be modified dependent upon the character of the current supply viz, the voltage and amperage for the appliance.

The components of the switch mechanism are supported upon a frame, which in the embodiment illustrated includes a frame plate 21 to which is secured a metal bushing or sleeve 22, the sleeve preferably having a flange portion 23 at one end and at its opposite end region is provided with a tenon portion 24 extending through an opening in the frame plate 21, the projecting portion of the tenon 24 being swaged as shown at 25 to secure the frame components 21 and 22 in fixed relation.

The extremity of the tenon is swaged into the position shown after the several components to be hereinafter described are assembled or mounted upon the sleeve 22 in the positions shown in FIGURES 1 and 3. The switch mechanism may be secured to a frame structure of the appliance or other support 26 by means of a bolt 28 extending through the hollow sleeve 22 and provided with a nut 29 which is drawn up to fixedly retain the switch mechanism to the support or frame 26.

The switch construction of the invention is inclusive of manually adjustable means operable within the operating temperature range of the switch for adjusting the position of one of the switch arms or switch members for current control at a desired temperature, the switch mechanism including a thermoresponsive means supplementing the manually adjustable means to maintain substantially constant the temperature for which the manual means is regulated or adjusted. In the embodiment illustrated the frame plate or frame component 21 of the switch mechanism is provided with a threaded opening to accommodate a threaded portion 32 of a shaft or member 34.

The shaft '34 is provided with a manipulating knob (not shown), the shaft 34 being arranged to be manually rotated relative to the frame plate 21. The frame plate or component 21 is provided with a pin or abutment 36 preferably provided with a tenon portion 37 driven into an opening formed in the plate 21 as shown in FIGURE 1. The shaft or member 34 is provided with a member or projection 4h for cooperation with the about'ment or stop member or pin 36 to limit the rotative movement of the shaft 34.

The member ttl is preferably fashioned with a tenon 42 snugly fitted in a transverse opening formed in the shaft 34. The abutment 36 and the member 40 on the shaft 34 cooperate to limit the maximum extent of rotation of the shaft 34, the extent of rotation defining the limits of the temperature range within which the switch is adapted to operate.

The switch mechanism of the invention is inclusive of two pairs or sets of switch arms, a thermoresponsive component or bimetallic element, terminal members or connectors, and means for providing for snap action of one of the switch arms or members actuated or controlled by the thermoresponsive means. A first pair of switch arms or members comprises a first switch arm 44 and a second switch arm 46, the arms respectively provided with cooperating contacts 45 and 47.

The second pair or set of switch arms comprises a third switch arm 48 and a fourth switch arm 59, the third and fourth switch arms being respectively provided with cooperating contacts 49 and 51, the second pair of switch arms being disposed above the first pair of switch arms. The contacts 4-5 and 47 make or interrupt the circuit through one side L1 of the current supply line and the contacts and 51 make or interrupt the circuit through the other side L2 of the current supply line. Nested or mounted upon the sleeve 22 are insulating discs, members or washers 54, 56, 58, 6t and 62 fashioned of ceramic, lava or other high temperature resistant insulating material.

The first switch arm td is in direct or metallic contact with a first terminal member 64, a tenon portion on the insulating washer 62 extending into openings formed in the switch member 44 and the terminal member 64. A support member or arm 66 disposed adjacent the switch arm 44 is provided with an opening and is received on the tenon formed on the washer 62, an insulating member or washer 68 of mica being disposed between the support arm 66 and the terminal member 64, the washer 68 being of mica or other suitable insulating material.

The terminal 64 is connected by lead 16 to one side 1.1 of a current supply. The first switch arm 44, the first terminal 64 and the support arm or member 66 are thus supported upon the tenon portion of the insulating washer The second switch arm 46 and the second terminal member 70 are supported upon a tenon portion formed on the insulating washer in the same manner as described in reference to the terminal 64 and the switch arm 44, the arm 46 and terminal '70 being in current conducting contact.

The third switch arm 48 and the third terminal 72 are mounted or supported in the same manner upon a tenon portion formed on the insulating washer 58. The fourth switch member 50 and the fourth terminal 74 are supported in like manner upon a tenon portion formed on the insulating washer 56. The terminal 74 is connected by a lead or conductor 14 with the other side L2 of a current source or supply. The terminals '70 and 72 are connnected by conductors '75 and 76 with the current con suming element 12 schematically illustrated in FIGURE 1.

The switch mechanism includes a thermoresponsive means or bimetallic element 80 supported by the sleeve 22, which extends through an opening in the element 80. Disposed in contact with the flange 23 of the sleeve 22 is a plate or member 82 which is spaced from the bimetallic element 80 by means of a washer 84. The plate or member 82 forms a stop or abutment means for limiting the downward movement or fiexure of the thermoresponsive element 89.

From the foregoing it will be seen that the two pairs or sets of switch arms, the therrnoresponsive means tit), the abutment plate 82, the support arm 66 and the four terminals are supported by the sleeve 22 of the switch frame construction.

After the assembly of these several components with the insulating washers on the sleeve 22 including the washers 54, 63 and 84, the portion of the tenon 24 extending through the frame plate 21. is swaged as shown at 25 to secure the components in fixed or assembled relation. The switch arms 44, 416, 48 and the support arm or member 66 are provided throughout a portion of their length with reinforcing ridges or flanges to effect hinging action of these components at a region adjacent the support.

Means is provided between the second switch arm 46 of the first pair of switch arms and the manually rotatable shaft for adjusting the relative position of this switch arm for the temperature desired for the appliance. The lower end region of the shaft 34 is provided with a bore 86 to receive one end of a strut 38 fashioned of high temperature resistant insulating material such as lava. The strut 83 extends through clearance openings 89 and Ml provided in the third and fourth switch arms 48 and 50, the lower end of the strut 88 having a cone-shaped extremity 92. which engages in a depression or recess fashioned in the second switch arm 46.

The switch arm as is normally stressed in an upward direction as viewed in FIGURE 1 so as to continuously bear against the strut 8S irrespective of the rotative position of the shaft 3 5. By rotation of the manipulating member or shaft 34 through the threaded connection of the shaft with the plate 2 1, the relative position of the second switch member 46 may be manually varied.

The thermoresponsive means or bimetallic element 30 is provided at its distal end region with a member or strut 92E of lava or ceramic which has a tenon portion 97 extending through an opening in the element and is secured thereto by means of a spring clip or retaining washer 98.

The arrangement embodies means for attaining a snap action of the switch arm 44 in making or interrupting the circuit through the contacts 45 and 47. A resilient or spring means 1% is associated with the arm or support member 66 and the switch arm 44 for establishing a snap action effective to rapidly open or close the contacts 45 and 47. The resilient means 108 is fashioned with a uniplanar or flat portion Th2 and a curved or arcuatelyshaped portion M4. The planar portion 102 is spot welded or otherwise fixedly joined to the support arm 66.

The arm 66 is formed with a struck-up projection 106 providing a stop means or abutment for limiting the downward movement or flexure of the switch arm 44 when the arm is moved downwardly to a position disengaging the contacts 45 and 47. The distal end region of the arcuate portion 1M is provided with a slot or opening into which extends a projection 198 formed on the end of the switch arm 44.

The region 11% adjacent the integral juncture of the arcuate portion 104 with the planar portion 102 is provided with an opening or is otherwise fashioned of reduced cross-section providing a weakened zone functioning as a hinge about which flexure of the arcuate portion 104 of the spring takes place in effecting movement of the switch arm or member 44. The construction of the spring 100 providing the snap action is of the character disclosed in my Patent 3,004,124, granted October 10, 1961.

It will be apparent that by flexing the planar portion 102 under the influence of the ceramic strut 96 actuated by movement of the thermoresponsive means or element 80, the arcuate portion will be actuated about the hinge or weakened zone 11% and the same moved upwardly or downwardly depending upon the direction of flexure to either side of the plane of the switch arm 44. In this manner, an effective toggle or snap action is provided imparting movement to the switch arm 44 through the arcuately shaped portion 1194 of the resilient means 1% to rapidly engage or disengage the contacts 45 and 47.

In the embodiment illustrated, the thermoresponsive means or bimetallic element St) is arranged to be flexedv upwardly by increased ambient temperature, which flexure engages the strut 96 with the planar portion 102, flexing the planar portion upwardly to a position wherein the toggle action of the spring moves the switch arm or member 44 downwardly with a snap action to quickly disengage the contacts and thereby avoid appreciable arcing.

When the temperature is reduced, the bimetallic element 80 is flexed downwardly and the strut )6 moves away from the portion Th2 and the inherent downward stress in the portion 102 flexes the arcuate portion 104 to move the switch member 1M upwardly with a snap action to engage the contacts 45 and 47.

The purpose of the second pair of switch arms 48 and 50 and their cooperating contacts 49 and 51 is to assure interrupting the other side L2 of the current supply line when the manually operable shaft 34 is rotated to an off position, that is a position in which the abutment 36 is engaged by the projection 40 and the strut 88 moved downwardly to its maximum lowermost position to positively separate the contacts 49 and 51. Fixedly secured to the distal end of the switch arm 46 is a tubular member 112, illustrated in cross-section in FIGURE 5, which is provided with exterior and interior threads.

Threaded interiorly of the member 112 is a second threaded member 114 provided with a recess in its lower end accommodatin the end region of a strut 116 fashioned of insulating material such as lava or ceramic, the lower end of the strut 116 engaging in a recess formed in the planar portion 102 of the resilient means 100. Mounted upon the member 112 is a circular member 113 of insulating material such as lava or the like, the member 118 being formed with a circular flange 12% which engages the upper surface of the end region of the switch arm 48.

The distal end of the switch arm 48 is fashioned with an open ended slot 122 providing the furcations 124 to receive the member 118. The member 118 is retained on the threaded member 112 by means of a securing nut 126 which is adjusted to engage the circular flange 120 in en gagement with the switch arm 48. When the shaft 34 is rotated to bring the strut 88 to its lowermost position, the switch arm 46 is moved downwardly and, through its connection with the threaded member 112, moves the member 113 downwardly whereby the circular flange 120 moves the switch arm 48 downwardly to positively disengage the contacts 49 and 51 thereby assuring that the circuit is interrupted when the shaft 34 is moved to its off position.

In the normal operation of the switch mechanism, the user rotates the shaft 34 to a position corresponding to the temperature at which it is desired to maintain the appliance, engagement of the contacts 49 and 51 establishing a circuit to the appliance. Thereafter the thermoresponsive means or bimetallic element 80, under the influence of ambient temperature variations, is effective to control the position of the spring means b to automatically interrupt and make the circuit through the contacts 45 and 47 so as to thereby maintain substantially constant the temperature of the appliance.

When the shaft 34 is rotated to its maximum on? position, the strut 88 is moved to its maximum downward position which, through the member 118, flexes the switch member or arm 48 downwardly to effect a disengagement of the contacts 49 and 51. The innermost threaded memher 114 within the threaded member 112 is adjustable in order to adjust the initial distance of separation between the support arm 66 and the switch arm 46 to obtain proper operation of the switch mechanism.

1 FIGURE 3 illustrates the position of the switch arms 48 and 50 with the contacts 49 and 51 out of engagement in an off position of the shaft 34. As the shaft 34 is moved from its oflf position to a temperature setting desired, the switch arm 46 which is normally stressed in an upward direction assumes a position for the temperature desired. Thereafter variations in ambient temperature affecting the thermoresponsive means 80, through the snap action of the resilient means 1% automatically effects engagement or disengagement of the contacts 45 and 4-7 to maintain substantially constant the temperature of the appliance for which the shaft 34 has been adjusted.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means, cooperating contacts carried by said pairs of switch members, manually actuable means mounted on the support means for adjusting the position of one switch member of the first pair, snap action thermoresponsive actuated means mounted on the support means to influence movement of the other switch member of the first pair, a tubular member carried by the switch member engaged by the manually actuable means, and an element of insulating material engaging the tubular member and having a portion engageable with a switch member of the second pair whereby movement of said manually actuable means to a predetermined position moves the said switch member of the second pair to separate the contacts carried by said second pair of switch members.

2. Switch mechanism comprising, in combination, support means, a first pair of switch membersmounted by the support means, a second pair of switch members mounted by the support means, cooperating contacts carried by the switch members of each pair, one pair of switch members being disposed to control one current supply line and the second pair being disposed to control the other current supply line, manuaHy actuable means mounted on the support means for adjusting the relative position of a switch member of the first pair, thermoresponsive means mounted on the support means to infiuence movement of the other switch member of the first pair, a cylindrical member carried by the switch member adjusted by said manually actuable means, a circular member of insulating material carried by the cylindrical member and engageable with a switch member of the second pair upon movement of said manually actuable means to a predetermined position to influence the relative position of the said switch member of the second pair to separate the contacts carried by the second pair of switch members, said first pair of switch members being disposed beneath the second pair of switch members.

3. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means, cooperating contacts carried by the switch members of each pair, one pair of switch members being in circuit with one current supply line and the second pair being in circuit with the other current supply line, manually actuable means mounted on the support means for adjusting the relative position of a switch member of one pair, thermoresponsive means mounted on the support means to influence movement of the other switch member of the same pair, means actuable upon movement of said manually actuable means to a predetermined position disposed to influence the relative position of a switch member of the second pair to separate the contacts carried by said second pair of switch members, a support arm mounted on the support means, articulate means between the support arm and the switch member controlled by the thermoresponsive means to provide snap action therefor, insulating strut means between said support arm and said switch member adjusted by said manually actuable means, said switch member adjusted by said manually actuable means and said switch member controlled by the thermoresponsive means being disposed beneath the other pair of switch members.

4. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means, cooperating contacts carried by the switch members of each pair, the first pair of switch members being disposed to control one current supply line and the second pair being disposed to control the other current supply line, manually actuable means mounted on the support means for adjusting the relative position of a switch member of the first pair, thermoresponsive means mounted on the support means to influence movement of the other switch member of the first pair, a sleeve secured to the switch member adjusted by the manually actuable means, an element of insulating material mounted on the sleeve, and abutment means on said insulating element engageable with a switch member of the second pair and being actuable upon movement of said manually actuable means to a predetermined position to move the said switch member of the second pair to separate the contacts carried by the second pair of switch members.

5. Switch mechanism comprising, in combination, support means, first and second pairs of switch members mounted by the support means, cooperating contacts carried by the switch members of each pair, the first pair of switch members being disposed to control one current supply line and the second pair being disposed to control the other current supply line, manually actuable means mounted on the support means for adjusting the relative position of a switch member of the first pair, thermoresponsive means mounted on the support means to infiuence movement of the other switch member of the first pair, a sleeve secured to the switch member adjusted by the manually actuable means, a support arm mounted on the support means, a resilient means dis posed between the support arm and the switch member influenced by the thermoresponsive means to provide snap action therefor, an insulating strut between the support arm and the sleeve, and an insulating bushing carried by said sleeve and engageable with a switch member of the second pair operable upon movement of said manually actuable means to a predetermined position to infiuence the relative position of said switch member of the second pair to separate the contacts carried by the second pair of switch members.

6. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means, cooperating contacts carried by said pairs of switch members, manually actuable means mounted on the support means for adjusting the position of one switch member of the first pair, thermoresponsive means mounted on the support means, an arm mounted on the support means, resilient means secured to said arm and connected with the other switch member of said first pair, a strut of insulating material carried by said thermoresponsive means disposed to cooperate with said resilient means to effect a snap action engagement and disengagement of the contacts carried by said first pair of switch members upon ambient temperature variations, a sleeve mounted on the switch member adjustable by the manually actuable means, and an insulating element carried by said sleeve engageable with a switch member of the second pair whereby movement of said manually actuable means to a predetermined position is effective through said sleeve and insulating element to separate the contacts carried by said second pair of switch members.

7. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means, cooperating contacts carried by said pairs of switch members, manually actuable means mounted on the supporting means for adjusting the position of one switch member of the first pair, thermoresponsive means mounted on the support means, an arm mounted on the support means, resilient means secured to said arm and connected with the second switch member of said first pair, a strut of insulating material carried by said thermoresponsive means disposed to cooperate with said resilient means to eifect a snap action engagement and disengagement of the contacts carried by said first pair of switch members upon ambient temperature variations, a cylindrical member secured to the switch member adjusted by said manually actuable means, an insulating element surrounding said cylindrical member having a shoulder engageable with a switch member of the second pair, means carried by the cylindrical member to limit movement of the insulating element in one direction relative to the cylindrical member, said shoulder on the insulating element moving the switch member engaged thereby upon movement of the manually actuable means to an off position to separate the contacts carried by the second pair of switch members.

8. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means wherein first and second members comprise one pair and third and fourth switch members comprise the second pair, cooperating contacts carried by said pairs of switch members, manually actuable means mounted by the support means for adjusting the position of the second switch member, thermoresponsive means mounted on the support means, an arm mounted on the support means disposed between the thermoresponsive means and the first switch member, an element having a planar portion secured to said arm and an arcuate portion, said arcuate portion having pivotal connection with the first switch member, said thermoresponsive means cooperating with said element to effect a snap action engagement and disengagement of the contacts carried by said first and second switch members upon ambient temperature variations, a sleeve mounted on the second switch member, and an insulating element carried by said sleeve engageable with the third switch member upon movement of said manually actuable means to an off position to effect a separation of the contacts carried by said third and fourth switch members.

9. Switch mechanism comprising, in combination, support means, two pairs of switch members mounted by the support means wherein first and second members comprise one pair and third and fourth switch members comprise the second pair, cooperating contacts carried by said pairs of switch members, manually actuable means mounted on the support means for adjusting the position of the second switch member, thermoresponsive means mounted on the support means, an arm mounted on the support means and disposed between the thermoresponsive means and the first switch member, an element having a planar portion secured to said arm and an areaate portion, said arcuate portion having pivotal connection with the first switch member, said thermoresponsive means cooperating with said element to effect a snap action engagement and disengagement of the contacts carried by said first and second switch members upon ambient temperature variations, a cylindrical member carried by said second switch member, an insulating means mounted by the cylindrical member engageable with the third switch member upon movement of said manually actuable means to an ofi position to eifect a separation of the contacts carried by said third and fourth switch members.

References Cited by the Examiner UNITED STATES PATENTS 2,847,553 8/58 Smith 200-138 3,004,124 10/61 Huffman 200138 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. SWITCH MECHANISM COMPRISING, IN COMBINATION, SUPPORT MEANS, TWO PAIRS OF SWITCH MEMBERS MOUNTED BY THE SUPPORT MEANS, COOPERATING CONTACTS CARRIED BY SAID PAIRS OF SWITCH MEMBERS, MANUALLY ACTUABLE MEANS MOUNTED ON THE SUPPORT MEANS FOR ADJUSTING THE POSITION OF ONE SWITCH MEMBER OF THE FIRST PAIR, SNAP ACTION THERMORESPONSIVE ACTUATED MEANS MOUNTED ON THE SUPPORT MEANS TO INFLUENCE MOVEMENT OF THE OTHER SWITCH MEMBER OF THE FIRST PAIR, A TUBULAR MEMBER CARRIED BY THE SWITCH MEMBER ENGAGED BY THE MANUALLY ACTUABLE MEANS, AND AN ELEMENT OF INSULATING MATERIAL ENGAGING THE TUBU- 